Are you fed up of constantly painting your windows and walls ? Perhaps you should try a Breathable Paint.
There are lots of different substrates you might want to paint – wood, brick, plaster. If you live in an older house, these materials will all be breathable. Thus if you “seal” these surfaces with an impermeable material, it will blister and get water trapped behind it. Use Breathable paint which works with your house, not against it.
Most commercial exterior paints (Dulux etc) contain acrylics and non permeable materials. These are introduced for a variety of reasons – ease of application , curing time etc etc. However, these paints create an impermeable film or crust over the timber. As the Timber expands and contracts (which ALL natural timber does) the paint cracks, peels and lets water in. The water cannot escape and causes decay.
Traditional paints would have been white lead based (white lead is the material, not the colour). This lasts a long time, does not trap moisture in and requires less maintenance. This is in contrast to modern gloss paint that essentially traps moisture in the timber / masonry, encourages rot and requires frequent maintenance.
Historic Lead based paints were very flexible and breathable and offered far superior protection and longevity. We cant use Lead paint anymore, so the next best thing is Linseed Oil Paint. It retains many of the benefits of Lead paint but without the H&S issues.
There is an extremely good explanation of the mechanics of Acrylic paints vs Linseed Paints on the Brouns website (a good supplier of Linseed Paint) – Link Here
We exclusively use Linseed paints on Timber now as it simply lasts much much longer than other types and does not decay the timber !
Do your windows look like the picture below…..Recently decorated and cracked peeling. In contract , below is a Door I painted with Linseed paint 6 years ago , still in good serviceable condition.
Typical Peeling Plastic Paint
Linsed Painted Door
Modern impermeable paints – Dulux Weathershied , Sandtex, External Masonry Paints, Masonry “coatings” for example are all unsuitable for old buildings.
The UK Building Regulations describe Traditional Buildings as; ‘buildings of traditional construction with permeable fabric that both absorbs and readily allows the evaporation of moisture’.
Modern impermeable paints do not allow the passage of moisture and “breathability” and as result can hold moisture in the walls and blister. There are many Breathable paints available that are permeable and will allow escape of moisture. Some of these paints are; Limewash, Clay Paint and Silicate Mineral Paint.
Be aware though – not all Breathable paints are equal. Limewash has the highest level of breathability , with some of the Silicate / Mineral Paints having some of the Lowest.
We have removed lots of Masonry paint – see Removing Paint from Brick Walls